diff --git a/CHANGELOG.md b/CHANGELOG.md
index 46103f244..a8604685d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,12 @@
 
 - Added `install_lucet_signal_handler()` and `remove_lucet_signal_handler()`, along with `Instance::ensure_signal_handler_installed()` and `Instance::ensure_sigstack_installed()` options to control the automatic installation and removal of signal handlers and alternate signal stacks. The default behaviors have not changed.
 
+- Added `Instance::run_start()` to the public API, which runs the [Wasm start function][start-function] if it is present in that instance's Wasm module. It does nothing if there is no start function.
+
+  Creating or resetting an instance no longer implicitly runs the start function. Embedders must ensure that `run_start()` is called before calling any other exported functions. `Instance::run()` will now return `Err(Error::InstanceNeedsStart)` if the start function is present but hasn't been run since the instance was created or reset.
+
+[start-function]: https://webassembly.github.io/spec/core/syntax/modules.html#syntax-start
+
 ### 0.6.1 (2020-02-18)
 
 - Added metadata to compiled modules that record whether instruction counting instrumentation is present.
diff --git a/Cargo.lock b/Cargo.lock
index a0d025cf6..a9f8ecdb2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -735,16 +735,16 @@ dependencies = [
 
 [[package]]
 name = "lucet-benchmarks"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
  "criterion 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.68 (registry+https://github.com/rust-lang/crates.io-index)",
- "lucet-module 0.6.2-dev",
- "lucet-runtime 0.6.2-dev",
- "lucet-runtime-internals 0.6.2-dev",
- "lucet-wasi 0.6.2-dev",
- "lucet-wasi-sdk 0.6.2-dev",
- "lucetc 0.6.2-dev",
+ "lucet-module 0.7.0-dev",
+ "lucet-runtime 0.7.0-dev",
+ "lucet-runtime-internals 0.7.0-dev",
+ "lucet-wasi 0.7.0-dev",
+ "lucet-wasi-sdk 0.7.0-dev",
+ "lucetc 0.7.0-dev",
  "nix 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 1.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rayon 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -753,7 +753,7 @@ dependencies = [
 
 [[package]]
 name = "lucet-module"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
  "anyhow 1.0.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "bincode 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -773,28 +773,28 @@ dependencies = [
 
 [[package]]
 name = "lucet-objdump"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
  "byteorder 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "colored 1.9.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "lucet-module 0.6.2-dev",
+ "lucet-module 0.7.0-dev",
  "object 0.18.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "lucet-runtime"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
  "anyhow 1.0.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "cc 1.0.50 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.68 (registry+https://github.com/rust-lang/crates.io-index)",
- "lucet-module 0.6.2-dev",
- "lucet-runtime-internals 0.6.2-dev",
- "lucet-runtime-tests 0.6.2-dev",
- "lucet-wasi-sdk 0.6.2-dev",
- "lucetc 0.6.2-dev",
+ "lucet-module 0.7.0-dev",
+ "lucet-runtime-internals 0.7.0-dev",
+ "lucet-runtime-tests 0.7.0-dev",
+ "lucet-wasi-sdk 0.7.0-dev",
+ "lucetc 0.7.0-dev",
  "nix 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-derive 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -806,13 +806,13 @@ dependencies = [
 name = "lucet-runtime-example"
 version = "0.1.0"
 dependencies = [
- "lucet-runtime 0.6.2-dev",
- "lucet-wasi 0.6.2-dev",
+ "lucet-runtime 0.7.0-dev",
+ "lucet-wasi 0.7.0-dev",
 ]
 
 [[package]]
 name = "lucet-runtime-internals"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
  "anyhow 1.0.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "bincode 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -823,8 +823,8 @@ dependencies = [
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.68 (registry+https://github.com/rust-lang/crates.io-index)",
  "libloading 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "lucet-module 0.6.2-dev",
- "lucet-runtime-macros 0.6.2-dev",
+ "lucet-module 0.7.0-dev",
+ "lucet-runtime-macros 0.7.0-dev",
  "memoffset 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "nix 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-derive 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -836,7 +836,7 @@ dependencies = [
 
 [[package]]
 name = "lucet-runtime-macros"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
  "quote 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 1.0.17 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -844,27 +844,27 @@ dependencies = [
 
 [[package]]
 name = "lucet-runtime-tests"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
  "anyhow 1.0.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "cc 1.0.50 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.68 (registry+https://github.com/rust-lang/crates.io-index)",
- "lucet-module 0.6.2-dev",
- "lucet-runtime-internals 0.6.2-dev",
- "lucet-wasi-sdk 0.6.2-dev",
- "lucetc 0.6.2-dev",
+ "lucet-module 0.7.0-dev",
+ "lucet-runtime-internals 0.7.0-dev",
+ "lucet-wasi-sdk 0.7.0-dev",
+ "lucetc 0.7.0-dev",
  "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "lucet-spectest"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
  "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "lucet-module 0.6.2-dev",
- "lucet-runtime 0.6.2-dev",
- "lucetc 0.6.2-dev",
+ "lucet-module 0.7.0-dev",
+ "lucet-runtime 0.7.0-dev",
+ "lucetc 0.7.0-dev",
  "serde 1.0.106 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.51 (registry+https://github.com/rust-lang/crates.io-index)",
  "target-lexicon 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -875,12 +875,12 @@ dependencies = [
 
 [[package]]
 name = "lucet-validate"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
  "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cranelift-entity 0.62.0",
- "lucet-wasi 0.6.2-dev",
- "lucet-wasi-sdk 0.6.2-dev",
+ "lucet-wasi 0.7.0-dev",
+ "lucet-wasi-sdk 0.7.0-dev",
  "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "thiserror 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "wabt 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -890,21 +890,21 @@ dependencies = [
 
 [[package]]
 name = "lucet-wasi"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
  "anyhow 1.0.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "cast 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "human-size 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.68 (registry+https://github.com/rust-lang/crates.io-index)",
- "lucet-module 0.6.2-dev",
- "lucet-runtime 0.6.2-dev",
- "lucet-runtime-internals 0.6.2-dev",
- "lucet-validate 0.6.2-dev",
- "lucet-wasi-generate 0.6.2-dev",
- "lucet-wasi-sdk 0.6.2-dev",
- "lucet-wiggle 0.6.2-dev",
- "lucetc 0.6.2-dev",
+ "lucet-module 0.7.0-dev",
+ "lucet-runtime 0.7.0-dev",
+ "lucet-runtime-internals 0.7.0-dev",
+ "lucet-validate 0.7.0-dev",
+ "lucet-wasi-generate 0.7.0-dev",
+ "lucet-wasi-sdk 0.7.0-dev",
+ "lucet-wiggle 0.7.0-dev",
+ "lucetc 0.7.0-dev",
  "nix 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -913,16 +913,16 @@ dependencies = [
 
 [[package]]
 name = "lucet-wasi-fuzz"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
  "anyhow 1.0.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.68 (registry+https://github.com/rust-lang/crates.io-index)",
- "lucet-module 0.6.2-dev",
- "lucet-runtime 0.6.2-dev",
- "lucet-wasi 0.6.2-dev",
- "lucet-wasi-sdk 0.6.2-dev",
- "lucetc 0.6.2-dev",
+ "lucet-module 0.7.0-dev",
+ "lucet-runtime 0.7.0-dev",
+ "lucet-wasi 0.7.0-dev",
+ "lucet-wasi-sdk 0.7.0-dev",
+ "lucetc 0.7.0-dev",
  "nix 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 1.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "progress 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -936,9 +936,9 @@ dependencies = [
 
 [[package]]
 name = "lucet-wasi-generate"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
- "lucet-wiggle 0.6.2-dev",
+ "lucet-wiggle 0.7.0-dev",
  "proc-macro2 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 1.0.17 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -948,13 +948,13 @@ dependencies = [
 
 [[package]]
 name = "lucet-wasi-sdk"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
  "anyhow 1.0.28 (registry+https://github.com/rust-lang/crates.io-index)",
- "lucet-module 0.6.2-dev",
- "lucet-validate 0.6.2-dev",
- "lucet-wasi 0.6.2-dev",
- "lucetc 0.6.2-dev",
+ "lucet-module 0.7.0-dev",
+ "lucet-validate 0.7.0-dev",
+ "lucet-wasi 0.7.0-dev",
+ "lucetc 0.7.0-dev",
  "target-lexicon 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "thiserror 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -962,13 +962,13 @@ dependencies = [
 
 [[package]]
 name = "lucet-wiggle"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
- "lucet-runtime 0.6.2-dev",
- "lucet-wasi-sdk 0.6.2-dev",
- "lucet-wiggle-generate 0.6.2-dev",
- "lucet-wiggle-macro 0.6.2-dev",
- "lucetc 0.6.2-dev",
+ "lucet-runtime 0.7.0-dev",
+ "lucet-wasi-sdk 0.7.0-dev",
+ "lucet-wiggle-generate 0.7.0-dev",
+ "lucet-wiggle-macro 0.7.0-dev",
+ "lucetc 0.7.0-dev",
  "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "wiggle 0.15.0",
  "wiggle-test 0.15.0",
@@ -976,10 +976,10 @@ dependencies = [
 
 [[package]]
 name = "lucet-wiggle-generate"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
  "heck 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "lucet-module 0.6.2-dev",
+ "lucet-module 0.7.0-dev",
  "proc-macro2 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 1.0.17 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -989,9 +989,9 @@ dependencies = [
 
 [[package]]
 name = "lucet-wiggle-macro"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
- "lucet-wiggle-generate 0.6.2-dev",
+ "lucet-wiggle-generate 0.7.0-dev",
  "quote 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 1.0.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "wiggle-generate 0.15.0",
@@ -1000,7 +1000,7 @@ dependencies = [
 
 [[package]]
 name = "lucetc"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 dependencies = [
  "anyhow 1.0.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "bimap 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1017,9 +1017,9 @@ dependencies = [
  "env_logger 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "human-size 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "lucet-module 0.6.2-dev",
- "lucet-validate 0.6.2-dev",
- "lucet-wiggle 0.6.2-dev",
+ "lucet-module 0.7.0-dev",
+ "lucet-validate 0.7.0-dev",
+ "lucet-wiggle 0.7.0-dev",
  "memoffset 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "minisign 0.5.15 (registry+https://github.com/rust-lang/crates.io-index)",
  "object 0.18.0 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/benchmarks/lucet-benchmarks/Cargo.toml b/benchmarks/lucet-benchmarks/Cargo.toml
index 18094f8dd..703aea4d9 100644
--- a/benchmarks/lucet-benchmarks/Cargo.toml
+++ b/benchmarks/lucet-benchmarks/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-benchmarks"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 description = "Benchmarks for the Lucet runtime"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
diff --git a/lucet-module/Cargo.toml b/lucet-module/Cargo.toml
index 414324425..5b0f815d0 100644
--- a/lucet-module/Cargo.toml
+++ b/lucet-module/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-module"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 description = "A structured interface for Lucet modules"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
diff --git a/lucet-module/src/functions.rs b/lucet-module/src/functions.rs
index 134450513..99495dbe5 100644
--- a/lucet-module/src/functions.rs
+++ b/lucet-module/src/functions.rs
@@ -125,9 +125,15 @@ impl OwnedFunctionMetadata {
     }
 }
 
+#[derive(Clone, Copy, Debug)]
 pub struct FunctionHandle {
     pub ptr: FunctionPointer,
     pub id: FunctionIndex,
+    /// This is `true` if and only if this handle was referenced through the start section.
+    ///
+    /// The same function may be referenced via other contexts, and will appear with `false` in this
+    /// field in those cases.
+    pub is_start_func: bool,
 }
 
 // The layout of this struct is very tightly coupled to lucetc's `write_function_manifest`!
diff --git a/lucet-objdump/Cargo.toml b/lucet-objdump/Cargo.toml
index 10aac027f..7f4384753 100644
--- a/lucet-objdump/Cargo.toml
+++ b/lucet-objdump/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-objdump"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 description = "Analyze object files emitted by the Lucet compiler"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
@@ -13,7 +13,7 @@ edition = "2018"
 object = "0.18"
 byteorder="1.2.1"
 colored="1.8.0"
-lucet-module = { path = "../lucet-module", version = "=0.6.2-dev" }
+lucet-module = { path = "../lucet-module", version = "=0.7.0-dev" }
 
 [package.metadata.deb]
 name = "fst-lucet-objdump"
diff --git a/lucet-runtime/Cargo.toml b/lucet-runtime/Cargo.toml
index 5562620c0..1de7eed59 100644
--- a/lucet-runtime/Cargo.toml
+++ b/lucet-runtime/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-runtime"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 description = "Pure Rust runtime for Lucet WebAssembly toolchain"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
@@ -11,17 +11,17 @@ edition = "2018"
 
 [dependencies]
 libc = "0.2.65"
-lucet-runtime-internals = { path = "lucet-runtime-internals", version = "=0.6.2-dev" }
-lucet-module = { path = "../lucet-module", version = "=0.6.2-dev" }
+lucet-runtime-internals = { path = "lucet-runtime-internals", version = "=0.7.0-dev" }
+lucet-module = { path = "../lucet-module", version = "=0.7.0-dev" }
 num-traits = "0.2"
 num-derive = "0.3.0"
 
 [dev-dependencies]
 byteorder = "1.2"
 lazy_static = "1.1"
-lucetc = { path = "../lucetc", version = "=0.6.2-dev" }
-lucet-runtime-tests = { path = "lucet-runtime-tests", version = "=0.6.2-dev" }
-lucet-wasi-sdk = { path = "../lucet-wasi-sdk", version = "=0.6.2-dev" }
+lucetc = { path = "../lucetc", version = "=0.7.0-dev" }
+lucet-runtime-tests = { path = "lucet-runtime-tests", version = "=0.7.0-dev" }
+lucet-wasi-sdk = { path = "../lucet-wasi-sdk", version = "=0.7.0-dev" }
 nix = "0.17"
 rayon = "1.0"
 tempfile = "3.0"
diff --git a/lucet-runtime/include/lucet.h b/lucet-runtime/include/lucet.h
index b360784ce..4d98151b8 100644
--- a/lucet-runtime/include/lucet.h
+++ b/lucet-runtime/include/lucet.h
@@ -33,6 +33,8 @@ uint32_t lucet_instance_heap_len(const struct lucet_instance *inst);
 
 void lucet_instance_release(struct lucet_instance *inst);
 
+enum lucet_error lucet_instance_run_start(struct lucet_instance *inst);
+
 enum lucet_error lucet_instance_reset(struct lucet_instance *inst);
 
 enum lucet_error lucet_instance_run(struct lucet_instance * inst,
diff --git a/lucet-runtime/include/lucet_types.h b/lucet-runtime/include/lucet_types.h
index a634e448b..fd4619aaf 100644
--- a/lucet-runtime/include/lucet_types.h
+++ b/lucet-runtime/include/lucet_types.h
@@ -30,6 +30,8 @@ enum lucet_error {
     lucet_error_dl,
     lucet_error_instance_not_returned,
     lucet_error_instance_not_yielded,
+    lucet_error_instance_needs_start,
+    lucet_error_start_already_run,
     lucet_error_start_yielded,
     lucet_error_internal,
     lucet_error_unsupported,
diff --git a/lucet-runtime/lucet-runtime-internals/Cargo.toml b/lucet-runtime/lucet-runtime-internals/Cargo.toml
index edd72bdb5..04c9e4d15 100644
--- a/lucet-runtime/lucet-runtime-internals/Cargo.toml
+++ b/lucet-runtime/lucet-runtime-internals/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-runtime-internals"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 description = "Pure Rust runtime for Lucet WebAssembly toolchain (internals)"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
@@ -10,8 +10,8 @@ authors = ["Lucet team <lucet@fastly.com>"]
 edition = "2018"
 
 [dependencies]
-lucet-module = { path = "../../lucet-module", version = "=0.6.2-dev" }
-lucet-runtime-macros = { path = "../lucet-runtime-macros", version = "=0.6.2-dev" }
+lucet-module = { path = "../../lucet-module", version = "=0.7.0-dev" }
+lucet-runtime-macros = { path = "../lucet-runtime-macros", version = "=0.7.0-dev" }
 
 anyhow = "1.0"
 bitflags = "1.0"
diff --git a/lucet-runtime/lucet-runtime-internals/src/c_api.rs b/lucet-runtime/lucet-runtime-internals/src/c_api.rs
index 1afa33301..e192d6bb5 100644
--- a/lucet-runtime/lucet-runtime-internals/src/c_api.rs
+++ b/lucet-runtime/lucet-runtime-internals/src/c_api.rs
@@ -78,6 +78,8 @@ pub enum lucet_error {
     Dl,
     InstanceNotReturned,
     InstanceNotYielded,
+    InstanceNeedsStart,
+    StartAlreadyRun,
     StartYielded,
     Internal,
     Unsupported,
@@ -104,6 +106,8 @@ impl From<&Error> for lucet_error {
             Error::DlError(_) => lucet_error::Dl,
             Error::InstanceNotReturned => lucet_error::InstanceNotReturned,
             Error::InstanceNotYielded => lucet_error::InstanceNotYielded,
+            Error::InstanceNeedsStart => lucet_error::InstanceNeedsStart,
+            Error::StartAlreadyRun => lucet_error::StartAlreadyRun,
             Error::StartYielded => lucet_error::StartYielded,
             Error::InternalError(_) => lucet_error::Internal,
             Error::Unsupported(_) => lucet_error::Unsupported,
diff --git a/lucet-runtime/lucet-runtime-internals/src/error.rs b/lucet-runtime/lucet-runtime-internals/src/error.rs
index 0e9e44afb..2d10271b1 100644
--- a/lucet-runtime/lucet-runtime-internals/src/error.rs
+++ b/lucet-runtime/lucet-runtime-internals/src/error.rs
@@ -55,6 +55,12 @@ pub enum Error {
     #[error("Instance not yielded")]
     InstanceNotYielded,
 
+    #[error("`Instance::run_start()` must be run before running other exported functions")]
+    InstanceNeedsStart,
+
+    #[error("`Instance::run_start()` called multiple times after a single instantiation or reset")]
+    StartAlreadyRun,
+
     #[error("Start function yielded")]
     StartYielded,
 
diff --git a/lucet-runtime/lucet-runtime-internals/src/instance.rs b/lucet-runtime/lucet-runtime-internals/src/instance.rs
index 1d0e65da5..480513c3c 100644
--- a/lucet-runtime/lucet-runtime-internals/src/instance.rs
+++ b/lucet-runtime/lucet-runtime-internals/src/instance.rs
@@ -11,7 +11,7 @@ use crate::alloc::{Alloc, HOST_PAGE_SIZE_EXPECTED};
 use crate::context::Context;
 use crate::embed_ctx::CtxMap;
 use crate::error::Error;
-use crate::module::{self, FunctionHandle, FunctionPointer, Global, GlobalValue, Module, TrapCode};
+use crate::module::{self, FunctionHandle, Global, GlobalValue, Module, TrapCode};
 use crate::region::RegionInternal;
 use crate::val::{UntypedRetVal, Val};
 use crate::WASM_PAGE_SIZE;
@@ -67,11 +67,6 @@ unsafe impl Send for InstanceHandle {}
 ///
 /// This is not meant for public consumption, but rather is used to make implementations of
 /// `Region`.
-///
-/// # Safety
-///
-/// This function runs the guest code for the WebAssembly `start` section, and running any guest
-/// code is potentially unsafe; see [`Instance::run()`](struct.Instance.html#method.run).
 pub fn new_instance_handle(
     instance: *mut Instance,
     module: Arc<dyn Module>,
@@ -256,8 +251,8 @@ pub struct Instance {
     /// Whether to install an alternate signal stack while the instance is running.
     ensure_sigstack_installed: bool,
 
-    /// Pointer to the function used as the entrypoint (for use in backtraces)
-    entrypoint: Option<FunctionPointer>,
+    /// Pointer to the function used as the entrypoint.
+    entrypoint: Option<FunctionHandle>,
 
     /// The value passed back to the guest when resuming a yielded instance.
     pub(crate) resumed_val: Option<Box<dyn Any + 'static>>,
@@ -530,9 +525,53 @@ impl Instance {
         self.swap_and_return()
     }
 
+    /// Run the module's [start function][start], if one exists.
+    ///
+    /// If there is no start function in the module, this does nothing.
+    ///
+    /// If the module contains a start function, you must run it before running any other exported
+    /// functions. If an instance is reset, you must run the start function again.
+    ///
+    /// Start functions may assume that Wasm tables and memories are properly initialized, but may
+    /// not assume that imported functions or globals are available.
+    ///
+    /// # Errors
+    ///
+    /// In addition to the errors that can be returned from [`Instance::run()`][run], this can also
+    /// return `Error::StartYielded` if the start function attempts to yield. This should not arise
+    /// as long as the start function does not attempt to use any imported functions.
+    ///
+    /// This also returns `Error::StartAlreadyRun` if the start function has already run since the
+    /// instance was created or last reset.
+    ///
+    /// Wasm start functions are not allowed to call imported functions. If the start function
+    /// attempts to do so, the instance will be terminated with
+    /// `TerminationDetails::StartCalledImportFunc`.
+    ///
+    /// # Safety
+    ///
+    /// The foreign code safety caveat of [`Instance::run()`][run]
+    /// applies.
+    ///
+    /// [run]: struct.Instance.html#method.run
+    /// [start]: https://webassembly.github.io/spec/core/syntax/modules.html#syntax-start
+    pub fn run_start(&mut self) -> Result<(), Error> {
+        if let Some(start) = self.module.get_start_func()? {
+            if !self.is_not_started() {
+                return Err(Error::StartAlreadyRun);
+            }
+            let res = self.run_func(start, &[])?;
+            if res.is_yielded() {
+                return Err(Error::StartYielded);
+            }
+        }
+        Ok(())
+    }
+
     /// Reset the instance's heap and global variables to their initial state.
     ///
-    /// The WebAssembly `start` section will also be run, if one exists.
+    /// The WebAssembly `start` section, if present, will need to be re-run with
+    /// [`Instance::run_start()`][run_start] before running any other exported functions.
     ///
     /// The embedder contexts present at instance creation or added with
     /// [`Instance::insert_embed_ctx()`](struct.Instance.html#method.insert_embed_ctx) are not
@@ -544,10 +583,7 @@ impl Instance {
     /// It is the embedder's responsibility to initialize new `KillSwitch`es after resetting an
     /// instance.
     ///
-    /// # Safety
-    ///
-    /// This function runs the guest code for the WebAssembly `start` section, and running any
-    /// guest code is potentially unsafe; see [`Instance::run()`](struct.Instance.html#method.run).
+    /// [run_start]: struct.Instance.html#method.run
     pub fn reset(&mut self) -> Result<(), Error> {
         self.alloc.reset_heap(self.module.as_ref())?;
         let globals = unsafe { self.alloc.globals_mut() };
@@ -564,9 +600,13 @@ impl Instance {
             };
         }
 
-        self.state = State::Ready;
+        if self.module.get_start_func()?.is_some() {
+            self.state = State::NotStarted;
+        } else {
+            self.state = State::Ready;
+        }
+
         self.kill_state = Arc::new(KillState::new());
-        self.run_start()?;
         Ok(())
     }
 
@@ -637,11 +677,6 @@ impl Instance {
     /// Insert a context value.
     ///
     /// If a context value of the same type already existed, it is returned.
-    ///
-    /// **Note**: this method is intended for embedder contexts that need to be added _after_ an
-    /// instance is created and initialized. To add a context for an instance's entire lifetime,
-    /// including the execution of its `start` section, see
-    /// [`Region::new_instance_builder()`](trait.Region.html#method.new_instance_builder).
     pub fn insert_embed_ctx<T: Any>(&mut self, x: T) -> Option<T> {
         self.embed_ctx.insert(x)
     }
@@ -750,6 +785,10 @@ impl Instance {
         KillSwitch::new(Arc::downgrade(&self.kill_state))
     }
 
+    pub fn is_not_started(&self) -> bool {
+        self.state.is_not_started()
+    }
+
     pub fn is_ready(&self) -> bool {
         self.state.is_ready()
     }
@@ -869,9 +908,17 @@ impl Instance {
 
     /// Run a function in guest context at the given entrypoint.
     fn run_func(&mut self, func: FunctionHandle, args: &[Val]) -> Result<RunResult, Error> {
-        if !(self.state.is_ready() || (self.state.is_faulted() && !self.state.is_fatal())) {
+        let needs_start = self.state.is_not_started() && !func.is_start_func;
+        if needs_start {
+            return Err(Error::InstanceNeedsStart);
+        }
+
+        let is_ready = self.state.is_ready();
+        let is_starting = self.state.is_not_started() && func.is_start_func;
+        let is_non_fatally_faulted = self.state.is_faulted() && !self.state.is_fatal();
+        if !(is_ready || is_starting || is_non_fatally_faulted) {
             return Err(Error::InvalidArgument(
-                "instance must be ready or non-fatally faulted",
+                "instance must be ready, starting, or non-fatally faulted",
             ));
         }
         if func.ptr.as_usize() == 0 {
@@ -899,7 +946,7 @@ impl Instance {
             }
         }
 
-        self.entrypoint = Some(func.ptr);
+        self.entrypoint = Some(func);
 
         let mut args_with_vmctx = vec![Val::from(self.alloc.slot().heap)];
         args_with_vmctx.extend_from_slice(args);
@@ -954,11 +1001,17 @@ impl Instance {
 
     /// The core routine for context switching into a guest, and extracting a result.
     ///
-    /// This must only be called for an instance in a ready, non-fatally faulted, or yielded
-    /// state. The public wrappers around this function should make sure the state is appropriate.
+    /// This must only be called for an instance in a ready, non-fatally faulted, or yielded state,
+    /// or in the not-started state on the start function. The public wrappers around this function
+    /// should make sure the state is appropriate.
     fn swap_and_return(&mut self) -> Result<RunResult, Error> {
+        let is_start_func = self
+            .entrypoint
+            .expect("we always have an entrypoint by now")
+            .is_start_func;
         debug_assert!(
             self.state.is_ready()
+                || self.state.is_not_started() && is_start_func
                 || (self.state.is_faulted() && !self.state.is_fatal())
                 || self.state.is_yielded()
         );
@@ -981,15 +1034,19 @@ impl Instance {
         if let Err(e) = res {
             // Something went wrong setting up or tearing down the signal handlers and signal
             // stack. This is an error, but we don't want it to mask an error that may have arisen
-            // due to a guest fault or guest termination. So, we set the state back to `Ready` only
-            // if it is still `Running`, which likely indicates we never even made it into the
-            // guest.
+            // due to a guest fault or guest termination. So, we set the state back to `Ready` or
+            // `NotStarted` only if it is still `Running`, which likely indicates we never even made
+            // it into the guest.
             //
             // As of 2020-03-20, the only early return points in the code above happen before the
-            // guest would be able to run, so this should always transition from running to ready if
-            // there's an error.
+            // guest would be able to run, so this should always transition from running to
+            // ready or not started if there's an error.
             if let State::Running = self.state {
-                self.state = State::Ready;
+                if is_start_func {
+                    self.state = State::NotStarted;
+                } else {
+                    self.state = State::Ready;
+                }
             }
             return Err(e);
         }
@@ -1068,9 +1125,14 @@ impl Instance {
                     Err(Error::RuntimeFault(details))
                 }
             }
-            State::Ready | State::Terminated | State::Yielded { .. } | State::Transitioning => Err(
-                lucet_format_err!("\"impossible\" state found in `swap_and_return()`: {}", st),
-            ),
+            State::NotStarted
+            | State::Ready
+            | State::Terminated
+            | State::Yielded { .. }
+            | State::Transitioning => Err(lucet_format_err!(
+                "\"impossible\" state found in `swap_and_return()`: {}",
+                st
+            )),
         }
     }
 
@@ -1096,16 +1158,6 @@ impl Instance {
 
         res
     }
-
-    fn run_start(&mut self) -> Result<(), Error> {
-        if let Some(start) = self.module.get_start_func()? {
-            let res = self.run_func(start, &[])?;
-            if res.is_yielded() {
-                return Err(Error::StartYielded);
-            }
-        }
-        Ok(())
-    }
 }
 
 /// Information about a runtime fault.
@@ -1157,10 +1209,6 @@ impl std::fmt::Display for FaultDetails {
 }
 
 /// Information about a terminated guest.
-///
-/// Guests are terminated either explicitly by `Vmctx::terminate()`, or implicitly by signal
-/// handlers that return `SignalBehavior::Terminate`. It usually indicates that an unrecoverable
-/// error has occurred in a hostcall, rather than in WebAssembly code.
 pub enum TerminationDetails {
     /// Returned when a signal handler terminates the instance.
     Signal,
@@ -1178,6 +1226,7 @@ pub enum TerminationDetails {
     BorrowError(&'static str),
     /// Calls to `lucet_hostcall_terminate` provide a payload for use by the embedder.
     Provided(Box<dyn Any + 'static>),
+    /// The instance was terminated by its `KillSwitch`.
     Remote,
 }
 
diff --git a/lucet-runtime/lucet-runtime-internals/src/instance/state.rs b/lucet-runtime/lucet-runtime-internals/src/instance/state.rs
index b1811b7ef..bb77d52da 100644
--- a/lucet-runtime/lucet-runtime-internals/src/instance/state.rs
+++ b/lucet-runtime/lucet-runtime-internals/src/instance/state.rs
@@ -7,6 +7,11 @@ use std::ffi::{CStr, CString};
 
 /// The representation of a Lucet instance's state machine.
 pub enum State {
+    /// The instance is freshly-created, but needs to run the start section before running other entrypoints.
+    ///
+    /// Transitions to `Running` when the start section is run, and then to `Ready` if it succeeds.
+    NotStarted,
+
     /// The instance is ready to run.
     ///
     /// Transitions to `Running` when the instance is run, or to `Ready` when it's reset.
@@ -21,7 +26,8 @@ pub enum State {
     /// The instance has faulted, potentially fatally.
     ///
     /// Transitions to `Faulted` when filling in additional fault details, to `Running` if
-    /// re-running a non-fatally faulted instance, or to `Ready` when the instance is reset.
+    /// re-running a non-fatally faulted instance, or to `Ready` or `NotStarted` when the instance
+    /// is reset.
     Faulted {
         details: FaultDetails,
         siginfo: libc::siginfo_t,
@@ -36,7 +42,7 @@ pub enum State {
 
     /// The instance has terminated, and must be reset before running again.
     ///
-    /// Transitions to `Ready` if the instance is reset.
+    /// Transitions to `Ready` or `NotStarted` if the instance is reset.
     Terminated,
 
     /// The instance is in the process of yielding.
@@ -54,7 +60,8 @@ pub enum State {
 
     /// The instance has yielded.
     ///
-    /// Transitions to `Running` if the instance is resumed, or to `Ready` if the instance is reset.
+    /// Transitions to `Running` if the instance is resumed, or to `Ready` or `NotStarted` if the
+    /// instance is reset.
     Yielded {
         /// A phantom value carrying the type of the expected resumption value.
         ///
@@ -76,6 +83,7 @@ pub enum State {
 impl std::fmt::Display for State {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
+            State::NotStarted => write!(f, "not started"),
             State::Ready => write!(f, "ready"),
             State::Running => write!(f, "running"),
             State::Faulted {
@@ -113,6 +121,14 @@ impl std::fmt::Display for State {
 }
 
 impl State {
+    pub fn is_not_started(&self) -> bool {
+        if let State::NotStarted { .. } = self {
+            true
+        } else {
+            false
+        }
+    }
+
     pub fn is_ready(&self) -> bool {
         if let State::Ready { .. } = self {
             true
diff --git a/lucet-runtime/lucet-runtime-internals/src/module.rs b/lucet-runtime/lucet-runtime-internals/src/module.rs
index d08ad2a8d..a171954b6 100644
--- a/lucet-runtime/lucet-runtime-internals/src/module.rs
+++ b/lucet-runtime/lucet-runtime-internals/src/module.rs
@@ -80,7 +80,11 @@ pub trait ModuleInternal: Send + Sync {
             .map(|(fn_id, _)| FunctionIndex::from_u32(fn_id as u32))
             .expect("valid function pointer");
 
-        FunctionHandle { ptr, id }
+        FunctionHandle {
+            ptr,
+            id,
+            is_start_func: false,
+        }
     }
 
     /// Look up an instruction pointer in the trap manifest.
diff --git a/lucet-runtime/lucet-runtime-internals/src/module/dl.rs b/lucet-runtime/lucet-runtime-internals/src/module/dl.rs
index 89f4cd332..69e69de5d 100644
--- a/lucet-runtime/lucet-runtime-internals/src/module/dl.rs
+++ b/lucet-runtime/lucet-runtime-internals/src/module/dl.rs
@@ -249,7 +249,11 @@ impl ModuleInternal for DlModule {
             .ok_or_else(|| Error::SymbolNotFound(sym.to_string()))
             .map(|id| {
                 let ptr = self.function_manifest()[id.as_u32() as usize].ptr();
-                FunctionHandle { ptr, id }
+                FunctionHandle {
+                    ptr,
+                    id,
+                    is_start_func: false,
+                }
             })
     }
 
@@ -274,9 +278,12 @@ impl ModuleInternal for DlModule {
             if start_func.is_null() {
                 lucet_incorrect_module!("`guest_start` is defined but null");
             }
-            Ok(Some(self.function_handle_from_ptr(
-                FunctionPointer::from_usize(unsafe { **start_func } as usize),
-            )))
+            let mut func = self
+                .function_handle_from_ptr(FunctionPointer::from_usize(
+                    unsafe { **start_func } as usize
+                ));
+            func.is_start_func = true;
+            Ok(Some(func))
         } else {
             Ok(None)
         }
diff --git a/lucet-runtime/lucet-runtime-internals/src/module/mock.rs b/lucet-runtime/lucet-runtime-internals/src/module/mock.rs
index 91964e354..0f642bdec 100644
--- a/lucet-runtime/lucet-runtime-internals/src/module/mock.rs
+++ b/lucet-runtime/lucet-runtime-internals/src/module/mock.rs
@@ -308,9 +308,12 @@ impl ModuleInternal for MockModule {
     }
 
     fn get_start_func(&self) -> Result<Option<FunctionHandle>, Error> {
-        Ok(self
-            .start_func
-            .map(|start| self.function_handle_from_ptr(start)))
+        let func = self.start_func.map(|start| {
+            let mut func = self.function_handle_from_ptr(start);
+            func.is_start_func = true;
+            func
+        });
+        Ok(func)
     }
 
     fn function_manifest(&self) -> &[FunctionSpec] {
diff --git a/lucet-runtime/lucet-runtime-internals/src/region.rs b/lucet-runtime/lucet-runtime-internals/src/region.rs
index 1f067497b..58a751b06 100644
--- a/lucet-runtime/lucet-runtime-internals/src/region.rs
+++ b/lucet-runtime/lucet-runtime-internals/src/region.rs
@@ -19,11 +19,6 @@ pub trait Region: RegionInternal {
     /// Calling `region.new_instance(module)` is shorthand for
     /// `region.new_instance_builder(module).build()` for use when further customization is
     /// unnecessary.
-    ///
-    /// # Safety
-    ///
-    /// This function runs the guest code for the WebAssembly `start` section, and running any guest
-    /// code is potentially unsafe; see [`Instance::run()`](struct.Instance.html#method.run).
     fn new_instance(&self, module: Arc<dyn Module>) -> Result<InstanceHandle, Error> {
         self.new_instance_builder(module).build()
     }
@@ -126,11 +121,6 @@ impl<'a> InstanceBuilder<'a> {
     }
 
     /// Build the instance.
-    ///
-    /// # Safety
-    ///
-    /// This function runs the guest code for the WebAssembly `start` section, and running any guest
-    /// code is potentially unsafe; see [`Instance::run()`](struct.Instance.html#method.run).
     pub fn build(self) -> Result<InstanceHandle, Error> {
         self.region
             .new_instance_with(self.module, self.embed_ctx, self.heap_memory_size_limit)
diff --git a/lucet-runtime/lucet-runtime-macros/Cargo.toml b/lucet-runtime/lucet-runtime-macros/Cargo.toml
index 91b8f57a0..e93c72ea8 100644
--- a/lucet-runtime/lucet-runtime-macros/Cargo.toml
+++ b/lucet-runtime/lucet-runtime-macros/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-runtime-macros"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 description = "Macros for the Lucet WebAssembly runtime"
 homepage = "https://github.com/bytecodealliance/lucet"
 repository = "https://github.com/bytecodealliance/lucet"
diff --git a/lucet-runtime/lucet-runtime-tests/Cargo.toml b/lucet-runtime/lucet-runtime-tests/Cargo.toml
index 21df47f97..15fbc28cc 100644
--- a/lucet-runtime/lucet-runtime-tests/Cargo.toml
+++ b/lucet-runtime/lucet-runtime-tests/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-runtime-tests"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 description = "Pure Rust runtime for Lucet WebAssembly toolchain (tests)"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
@@ -19,10 +19,10 @@ anyhow = "1"
 lazy_static = "1.1"
 libc = "0.2.65"
 tempfile = "3.0"
-lucet-module = { path = "../../lucet-module", version = "=0.6.2-dev" }
-lucet-runtime-internals = { path = "../lucet-runtime-internals", version = "=0.6.2-dev" }
-lucet-wasi-sdk = { path = "../../lucet-wasi-sdk", version = "=0.6.2-dev" }
-lucetc = { path = "../../lucetc", version = "=0.6.2-dev" }
+lucet-module = { path = "../../lucet-module", version = "=0.7.0-dev" }
+lucet-runtime-internals = { path = "../lucet-runtime-internals", version = "=0.7.0-dev" }
+lucet-wasi-sdk = { path = "../../lucet-wasi-sdk", version = "=0.7.0-dev" }
+lucetc = { path = "../../lucetc", version = "=0.7.0-dev" }
 
 [build-dependencies]
 cc = "1.0"
diff --git a/lucet-runtime/lucet-runtime-tests/src/guest_fault.rs b/lucet-runtime/lucet-runtime-tests/src/guest_fault.rs
index 98de17062..88616a964 100644
--- a/lucet-runtime/lucet-runtime-tests/src/guest_fault.rs
+++ b/lucet-runtime/lucet-runtime-tests/src/guest_fault.rs
@@ -1,9 +1,7 @@
 #[macro_export]
 macro_rules! guest_fault_common_defs {
     () => {
-        use common::{
-            mock_traps_module, with_unchanged_signal_handlers, HOSTCALL_TEST_ERROR, RECOVERABLE_PTR,
-        };
+        use common::{mock_traps_module, HOSTCALL_TEST_ERROR, RECOVERABLE_PTR};
         pub mod common {
             use lucet_module::{FunctionPointer, TrapCode, TrapSite};
             use lucet_runtime::vmctx::{lucet_vmctx, Vmctx};
@@ -161,36 +159,6 @@ macro_rules! guest_fault_common_defs {
                     ))
                     .build()
             }
-
-            pub fn with_unchanged_signal_handlers<F: FnOnce()>(f: F) {
-                fn get_handlers() -> Vec<libc::sigaction> {
-                    use libc::*;
-                    use std::mem::MaybeUninit;
-                    const SIGNALS: &'static [c_int] = &[SIGBUS, SIGFPE, SIGILL, SIGSEGV, SIGALRM];
-
-                    SIGNALS
-                        .iter()
-                        .map(|sig| unsafe {
-                            let mut out = MaybeUninit::<sigaction>::uninit();
-                            sigaction(*sig, std::ptr::null(), out.as_mut_ptr());
-                            out.assume_init()
-                        })
-                        .collect()
-                }
-
-                let before = get_handlers();
-
-                f();
-
-                let after = get_handlers();
-
-                for (before, after) in before.into_iter().zip(after.into_iter()) {
-                    assert_eq!(
-                        before.sa_sigaction, after.sa_sigaction,
-                        "signal handlers match before and after"
-                    );
-                }
-            }
         }
 
         #[test]
@@ -218,7 +186,8 @@ macro_rules! guest_fault_tests {
         use std::sync::{Arc, Mutex};
         use $TestRegion as TestRegion;
         use $crate::helpers::{
-            test_ex, test_nonex, FunctionPointer, MockExportBuilder, MockModuleBuilder,
+            test_ex, test_nonex, with_unchanged_signal_handlers, FunctionPointer,
+            MockExportBuilder, MockModuleBuilder,
         };
 
         lazy_static! {
diff --git a/lucet-runtime/lucet-runtime-tests/src/helpers.rs b/lucet-runtime/lucet-runtime-tests/src/helpers.rs
index a73ee55a6..b135880dd 100644
--- a/lucet-runtime/lucet-runtime-tests/src/helpers.rs
+++ b/lucet-runtime/lucet-runtime-tests/src/helpers.rs
@@ -37,3 +37,33 @@ where
     drop(lock);
     r
 }
+
+pub fn with_unchanged_signal_handlers<F: FnOnce()>(f: F) {
+    fn get_handlers() -> Vec<libc::sigaction> {
+        use libc::*;
+        use std::mem::MaybeUninit;
+        const SIGNALS: &'static [c_int] = &[SIGBUS, SIGFPE, SIGILL, SIGSEGV, SIGALRM];
+
+        SIGNALS
+            .iter()
+            .map(|sig| unsafe {
+                let mut out = MaybeUninit::<sigaction>::uninit();
+                sigaction(*sig, std::ptr::null(), out.as_mut_ptr());
+                out.assume_init()
+            })
+            .collect()
+    }
+
+    let before = get_handlers();
+
+    f();
+
+    let after = get_handlers();
+
+    for (before, after) in before.into_iter().zip(after.into_iter()) {
+        assert_eq!(
+            before.sa_sigaction, after.sa_sigaction,
+            "signal handlers match before and after"
+        );
+    }
+}
diff --git a/lucet-runtime/lucet-runtime-tests/src/start.rs b/lucet-runtime/lucet-runtime-tests/src/start.rs
index 45983aef6..cf6a006ce 100644
--- a/lucet-runtime/lucet-runtime-tests/src/start.rs
+++ b/lucet-runtime/lucet-runtime-tests/src/start.rs
@@ -1,10 +1,11 @@
 #[macro_export]
 macro_rules! start_tests {
     ( $TestRegion:path ) => {
-        use lucet_runtime::{DlModule, Limits, Region};
+        use lucet_runtime::{DlModule, Error, Limits, Region};
         use std::sync::Arc;
         use $TestRegion as TestRegion;
         use $crate::build::test_module_wasm;
+        use $crate::helpers::{test_ex, test_nonex, with_unchanged_signal_handlers};
 
         #[test]
         fn ensure_linked() {
@@ -13,62 +14,252 @@ macro_rules! start_tests {
 
         #[test]
         fn global_init() {
-            let module =
-                test_module_wasm("start", "global_init.wat").expect("module compiled and loaded");
-            let region = TestRegion::create(1, &Limits::default()).expect("region can be created");
-            let mut inst = region
-                .new_instance(module)
-                .expect("instance can be created");
-
-            inst.run("main", &[]).expect("instance runs");
-
-            // Now the globals should be:
-            // $flossie = 17
-            // and heap should be:
-            // [0] = 17
-
-            let heap = inst.heap_u32();
-            assert_eq!(heap[0], 17);
+            test_nonex(|| {
+                let module = test_module_wasm("start", "global_init.wat")
+                    .expect("module compiled and loaded");
+                let region =
+                    TestRegion::create(1, &Limits::default()).expect("region can be created");
+                let mut inst = region
+                    .new_instance(module)
+                    .expect("instance can be created");
+
+                inst.run_start().expect("start section runs");
+                inst.run("main", &[]).expect("instance runs");
+
+                // Now the globals should be:
+                // $flossie = 17
+                // and heap should be:
+                // [0] = 17
+
+                let heap = inst.heap_u32();
+                assert_eq!(heap[0], 17);
+            });
         }
 
         #[test]
         fn start_and_call() {
-            let module = test_module_wasm("start", "start_and_call.wat")
-                .expect("module compiled and loaded");
-            let region = TestRegion::create(1, &Limits::default()).expect("region can be created");
-            let mut inst = region
-                .new_instance(module)
-                .expect("instance can be created");
-
-            inst.run("main", &[]).expect("instance runs");
-
-            // Now the globals should be:
-            // $flossie = 17
-            // and heap should be:
-            // [0] = 17
-
-            let heap = inst.heap_u32();
-            assert_eq!(heap[0], 17);
+            test_nonex(|| {
+                let module = test_module_wasm("start", "start_and_call.wat")
+                    .expect("module compiled and loaded");
+                let region =
+                    TestRegion::create(1, &Limits::default()).expect("region can be created");
+                let mut inst = region
+                    .new_instance(module)
+                    .expect("instance can be created");
+
+                inst.run_start().expect("start section runs");
+                inst.run("main", &[]).expect("instance runs");
+
+                // Now the globals should be:
+                // $flossie = 17
+                // and heap should be:
+                // [0] = 17
+
+                let heap = inst.heap_u32();
+                assert_eq!(heap[0], 17);
+            });
+        }
+
+        #[test]
+        fn start_is_required() {
+            test_nonex(|| {
+                let module = test_module_wasm("start", "start_and_call.wat")
+                    .expect("module compiled and loaded");
+                let region =
+                    TestRegion::create(1, &Limits::default()).expect("region can be created");
+                let mut inst = region
+                    .new_instance(module)
+                    .expect("instance can be created");
+
+                match inst.run("main", &[]).unwrap_err() {
+                    Error::InstanceNeedsStart => (),
+                    e => panic!("unexpected error: {}", e),
+                }
+            });
+        }
+
+        #[test]
+        fn no_start_without_reset() {
+            test_nonex(|| {
+                let module = test_module_wasm("start", "start_and_call.wat")
+                    .expect("module compiled and loaded");
+                let region =
+                    TestRegion::create(1, &Limits::default()).expect("region can be created");
+                let mut inst = region
+                    .new_instance(module)
+                    .expect("instance can be created");
+
+                inst.run_start().expect("start section runs");
+                match inst.run_start().unwrap_err() {
+                    Error::StartAlreadyRun => (),
+                    e => panic!("unexpected error: {}", e),
+                }
+            });
+        }
+
+        #[test]
+        fn start_and_reset() {
+            test_nonex(|| {
+                let module = test_module_wasm("start", "start_and_call.wat")
+                    .expect("module compiled and loaded");
+                let region =
+                    TestRegion::create(1, &Limits::default()).expect("region can be created");
+                let mut inst = region
+                    .new_instance(module)
+                    .expect("instance can be created");
+
+                inst.run_start().expect("start section runs");
+                inst.run("main", &[]).expect("instance runs");
+
+                // Now the globals should be:
+                // $flossie = 17
+                // and heap should be:
+                // [0] = 17
+
+                let heap = inst.heap_u32();
+                assert_eq!(heap[0], 17);
+
+                inst.reset().expect("instance resets");
+
+                let heap = inst.heap_u32();
+                assert_eq!(heap[0], 0);
+
+                inst.run_start().expect("start section runs again");
+                inst.run("main", &[]).expect("instance runs again");
+
+                let heap = inst.heap_u32();
+                assert_eq!(heap[0], 17);
+            });
         }
 
         #[test]
         fn no_start() {
-            let module =
-                test_module_wasm("start", "no_start.wat").expect("module compiled and loaded");
-            let region = TestRegion::create(1, &Limits::default()).expect("region can be created");
-            let mut inst = region
-                .new_instance(module)
-                .expect("instance can be created");
-
-            inst.run("main", &[]).expect("instance runs");
-
-            // Now the globals should be:
-            // $flossie = 17
-            // and heap should be:
-            // [0] = 17
-
-            let heap = inst.heap_u32();
-            assert_eq!(heap[0], 17);
+            test_nonex(|| {
+                let module =
+                    test_module_wasm("start", "no_start.wat").expect("module compiled and loaded");
+                let region =
+                    TestRegion::create(1, &Limits::default()).expect("region can be created");
+                let mut inst = region
+                    .new_instance(module)
+                    .expect("instance can be created");
+
+                inst.run_start().expect("start section doesn't run");
+                inst.run("main", &[]).expect("instance runs");
+
+                // Now the globals should be:
+                // $flossie = 17
+                // and heap should be:
+                // [0] = 17
+
+                let heap = inst.heap_u32();
+                assert_eq!(heap[0], 17);
+            });
+        }
+
+        #[test]
+        fn manual_signal_handler_ok() {
+            test_ex(|| {
+                with_unchanged_signal_handlers(|| {
+                    let module = test_module_wasm("start", "start_and_call.wat")
+                        .expect("module compiled and loaded");
+                    let region =
+                        TestRegion::create(1, &Limits::default()).expect("region can be created");
+                    let mut inst = region
+                        .new_instance(module)
+                        .expect("instance can be created");
+
+                    inst.ensure_signal_handler_installed(false);
+                    lucet_runtime::install_lucet_signal_handler();
+
+                    inst.run_start().expect("start section runs");
+                    inst.run("main", &[]).expect("instance runs");
+
+                    // Now the globals should be:
+                    // $flossie = 17
+                    // and heap should be:
+                    // [0] = 17
+
+                    let heap = inst.heap_u32();
+                    assert_eq!(heap[0], 17);
+
+                    inst.reset().expect("instance resets");
+
+                    let heap = inst.heap_u32();
+                    assert_eq!(heap[0], 0);
+
+                    inst.run_start().expect("start section runs again");
+                    inst.run("main", &[]).expect("instance runs again");
+
+                    let heap = inst.heap_u32();
+                    assert_eq!(heap[0], 17);
+
+                    lucet_runtime::remove_lucet_signal_handler();
+                })
+            });
+        }
+
+        #[test]
+        fn manual_sigstack_ok() {
+            test_nonex(|| {
+                use libc::*;
+                use std::mem::MaybeUninit;
+
+                let mut our_sigstack_alloc = vec![0; lucet_runtime::DEFAULT_SIGNAL_STACK_SIZE];
+                let our_sigstack = stack_t {
+                    ss_sp: our_sigstack_alloc.as_mut_ptr() as *mut _,
+                    ss_flags: 0,
+                    ss_size: lucet_runtime::DEFAULT_SIGNAL_STACK_SIZE,
+                };
+                let mut beforestack = MaybeUninit::<stack_t>::uninit();
+                let beforestack = unsafe {
+                    sigaltstack(&our_sigstack, beforestack.as_mut_ptr());
+                    beforestack.assume_init()
+                };
+
+                let module = test_module_wasm("start", "start_and_call.wat")
+                    .expect("module compiled and loaded");
+                let limits_no_sigstack = Limits {
+                    signal_stack_size: 0,
+                    ..Limits::default()
+                };
+                let region =
+                    TestRegion::create(1, &limits_no_sigstack).expect("region can be created");
+                let mut inst = region
+                    .new_instance(module)
+                    .expect("instance can be created");
+
+                inst.ensure_sigstack_installed(false);
+
+                inst.run_start().expect("start section runs");
+                inst.run("main", &[]).expect("instance runs");
+
+                // Now the globals should be:
+                // $flossie = 17
+                // and heap should be:
+                // [0] = 17
+
+                let heap = inst.heap_u32();
+                assert_eq!(heap[0], 17);
+
+                inst.reset().expect("instance resets");
+
+                let heap = inst.heap_u32();
+                assert_eq!(heap[0], 0);
+
+                inst.run_start().expect("start section runs again");
+                inst.run("main", &[]).expect("instance runs again");
+
+                let heap = inst.heap_u32();
+                assert_eq!(heap[0], 17);
+
+                let mut afterstack = MaybeUninit::<stack_t>::uninit();
+                let afterstack = unsafe {
+                    sigaltstack(&beforestack, afterstack.as_mut_ptr());
+                    afterstack.assume_init()
+                };
+
+                assert_eq!(afterstack.ss_sp, our_sigstack_alloc.as_mut_ptr() as *mut _);
+            });
         }
     };
 }
diff --git a/lucet-runtime/src/c_api.rs b/lucet-runtime/src/c_api.rs
index e8efdd144..2428636f9 100644
--- a/lucet-runtime/src/c_api.rs
+++ b/lucet-runtime/src/c_api.rs
@@ -48,6 +48,8 @@ pub extern "C" fn lucet_error_name(e: c_int) -> *const c_char {
             Dl => "lucet_error_dl\0".as_ptr() as _,
             InstanceNotReturned => "lucet_error_instance_not_returned\0".as_ptr() as _,
             InstanceNotYielded => "lucet_error_instance_not_yielded\0".as_ptr() as _,
+            InstanceNeedsStart => "lucet_error_instance_needs_start\0".as_ptr() as _,
+            StartAlreadyRun => "lucet_error_start_already_run\0".as_ptr() as _,
             StartYielded => "lucet_error_start_yielded\0".as_ptr() as _,
             Internal => "lucet_error_internal\0".as_ptr() as _,
             Unsupported => "lucet_error_unsupported\0".as_ptr() as _,
@@ -242,6 +244,15 @@ pub unsafe extern "C" fn lucet_instance_resume(
     })
 }
 
+#[no_mangle]
+pub unsafe extern "C" fn lucet_instance_run_start(inst: *mut lucet_instance) -> lucet_error {
+    with_instance_ptr!(inst, {
+        inst.run_start()
+            .map(|_| lucet_error::Ok)
+            .unwrap_or_else(|e| e.into())
+    })
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn lucet_instance_reset(inst: *mut lucet_instance) -> lucet_error {
     with_instance_ptr!(inst, {
diff --git a/lucet-spectest/Cargo.toml b/lucet-spectest/Cargo.toml
index fece6a067..ef33fe3bb 100644
--- a/lucet-spectest/Cargo.toml
+++ b/lucet-spectest/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-spectest"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 description = "Test harness to run WebAssembly spec tests (.wast) against the Lucet toolchain"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
@@ -17,9 +17,9 @@ name = "spec-test"
 path = "src/main.rs"
 
 [dependencies]
-lucetc = { path = "../lucetc", version = "=0.6.2-dev" }
-lucet-module = { path = "../lucet-module", version = "=0.6.2-dev" }
-lucet-runtime = { path = "../lucet-runtime", version = "=0.6.2-dev" }
+lucetc = { path = "../lucetc", version = "=0.7.0-dev" }
+lucet-module = { path = "../lucet-module", version = "=0.7.0-dev" }
+lucet-runtime = { path = "../lucet-runtime", version = "=0.7.0-dev" }
 wabt = "0.9.2"
 serde = "1.0"
 serde_json = "1.0"
diff --git a/lucet-validate/Cargo.toml b/lucet-validate/Cargo.toml
index d847555fb..f861f6907 100644
--- a/lucet-validate/Cargo.toml
+++ b/lucet-validate/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-validate"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 description = "Parse and validate webassembly files against witx interface"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
@@ -24,8 +24,8 @@ thiserror = "1.0.4"
 wasmparser = "0.51.2"
 
 [dev-dependencies]
-lucet-wasi = { path = "../lucet-wasi", version = "=0.6.2-dev" }
-lucet-wasi-sdk = { path = "../lucet-wasi-sdk", version = "=0.6.2-dev" }
+lucet-wasi = { path = "../lucet-wasi", version = "=0.7.0-dev" }
+lucet-wasi-sdk = { path = "../lucet-wasi-sdk", version = "=0.7.0-dev" }
 tempfile = "3.0"
 wabt = "0.9.2"
 
diff --git a/lucet-wasi-fuzz/Cargo.toml b/lucet-wasi-fuzz/Cargo.toml
index 501a2040d..310a8bdab 100644
--- a/lucet-wasi-fuzz/Cargo.toml
+++ b/lucet-wasi-fuzz/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-wasi-fuzz"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 description = "Test the Lucet toolchain against native code execution using Csmith"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
diff --git a/lucet-wasi-sdk/Cargo.toml b/lucet-wasi-sdk/Cargo.toml
index 70f7acce1..7a76dded8 100644
--- a/lucet-wasi-sdk/Cargo.toml
+++ b/lucet-wasi-sdk/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-wasi-sdk"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 description = "A Rust interface to the wasi-sdk compiler and linker"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
@@ -10,13 +10,13 @@ authors = ["Lucet team <lucet@fastly.com>"]
 edition = "2018"
 
 [dependencies]
-lucetc = { path = "../lucetc", version = "=0.6.2-dev" }
-lucet-module = { path = "../lucet-module", version = "=0.6.2-dev" }
+lucetc = { path = "../lucetc", version = "=0.7.0-dev" }
+lucet-module = { path = "../lucet-module", version = "=0.7.0-dev" }
 tempfile = "3.0"
 thiserror = "1.0.4"
 
 [dev-dependencies]
 anyhow = "1"
-lucet-validate = { path = "../lucet-validate", version  = "=0.6.2-dev" }
-lucet-wasi = { path = "../lucet-wasi", version  = "=0.6.2-dev" }
+lucet-validate = { path = "../lucet-validate", version  = "=0.7.0-dev" }
+lucet-wasi = { path = "../lucet-wasi", version  = "=0.7.0-dev" }
 target-lexicon = "0.10"
diff --git a/lucet-wasi/Cargo.toml b/lucet-wasi/Cargo.toml
index 085ec69d2..11a418b2f 100644
--- a/lucet-wasi/Cargo.toml
+++ b/lucet-wasi/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-wasi"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 description = "Fastly's runtime for the WebAssembly System Interface (WASI)"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
@@ -14,11 +14,11 @@ anyhow = "1"
 cast = "0.2"
 clap = "2.23"
 human-size = "0.4"
-lucet-runtime = { path = "../lucet-runtime", version = "=0.6.2-dev"  }
-lucet-runtime-internals = { path = "../lucet-runtime/lucet-runtime-internals", version = "=0.6.2-dev" }
-lucet-module = { path = "../lucet-module", version = "=0.6.2-dev" }
-lucet-wasi-generate = { path = "./generate", version = "=0.6.2-dev" }
-lucet-wiggle = { path = "../lucet-wiggle", version = "=0.6.2-dev" }
+lucet-runtime = { path = "../lucet-runtime", version = "=0.7.0-dev"  }
+lucet-runtime-internals = { path = "../lucet-runtime/lucet-runtime-internals", version = "=0.7.0-dev" }
+lucet-module = { path = "../lucet-module", version = "=0.7.0-dev" }
+lucet-wasi-generate = { path = "./generate", version = "=0.7.0-dev" }
+lucet-wiggle = { path = "../lucet-wiggle", version = "=0.7.0-dev" }
 libc = "0.2.65"
 nix = "0.17"
 rand = "0.6"
diff --git a/lucet-wasi/generate/Cargo.toml b/lucet-wasi/generate/Cargo.toml
index 7817888ba..1e82697ed 100644
--- a/lucet-wasi/generate/Cargo.toml
+++ b/lucet-wasi/generate/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-wasi-generate"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
 license = "Apache-2.0 WITH LLVM-exception"
@@ -12,7 +12,7 @@ edition = "2018"
 proc-macro = true
 
 [dependencies]
-lucet-wiggle = { path = "../../lucet-wiggle", version = "0.6.2-dev" }
+lucet-wiggle = { path = "../../lucet-wiggle", version = "0.7.0-dev" }
 wasi-common = { path = "../../wasmtime/crates/wasi-common",  version = "0.15.0", features = ["wiggle_metadata"] }
 wiggle-generate = { path = "../../wasmtime/crates/wiggle/generate",  version = "0.15.0" }
 syn = { version = "1.0", features = ["full"] }
diff --git a/lucet-wasi/src/main.rs b/lucet-wasi/src/main.rs
index e725b9772..34c7f95b3 100644
--- a/lucet-wasi/src/main.rs
+++ b/lucet-wasi/src/main.rs
@@ -258,6 +258,8 @@ fn run(config: Config<'_>) {
             });
         }
 
+        inst.run_start().expect("Wasm start function runs");
+
         match inst.run(config.entrypoint, &[]) {
             // normal termination implies 0 exit code
             Ok(RunResult::Returned(_)) => 0,
diff --git a/lucet-wiggle/Cargo.toml b/lucet-wiggle/Cargo.toml
index 06075eea4..ed8781b86 100644
--- a/lucet-wiggle/Cargo.toml
+++ b/lucet-wiggle/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-wiggle"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
 license = "Apache-2.0 WITH LLVM-exception"
@@ -11,13 +11,13 @@ edition = "2018"
 [lib]
 
 [dependencies]
-lucet-wiggle-macro = { path = "./macro", version = "0.6.2-dev" }
-lucet-wiggle-generate = { path = "./generate", version = "0.6.2-dev" }
-lucet-runtime = { path = "../lucet-runtime", version = "0.6.2-dev" }
+lucet-wiggle-macro = { path = "./macro", version = "0.7.0-dev" }
+lucet-wiggle-generate = { path = "./generate", version = "0.7.0-dev" }
+lucet-runtime = { path = "../lucet-runtime", version = "0.7.0-dev" }
 wiggle =  { path = "../wasmtime/crates/wiggle", version = "0.15.0" }
 
 [dev-dependencies]
 wiggle-test = { path = "../wasmtime/crates/wiggle/test-helpers" }
 tempfile = "3.1"
-lucet-wasi-sdk = { path = "../lucet-wasi-sdk", version = "0.6.2-dev" }
-lucetc = { path = "../lucetc", version = "0.6.2-dev" }
+lucet-wasi-sdk = { path = "../lucet-wasi-sdk", version = "0.7.0-dev" }
+lucetc = { path = "../lucetc", version = "0.7.0-dev" }
diff --git a/lucet-wiggle/generate/Cargo.toml b/lucet-wiggle/generate/Cargo.toml
index 22bd52e03..82e7dc4e4 100644
--- a/lucet-wiggle/generate/Cargo.toml
+++ b/lucet-wiggle/generate/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-wiggle-generate"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
 license = "Apache-2.0 WITH LLVM-exception"
@@ -10,7 +10,7 @@ edition = "2018"
 
 [dependencies]
 wiggle-generate = { path = "../../wasmtime/crates/wiggle/generate", version = "0.15.0" }
-lucet-module = { path = "../../lucet-module", version = "0.6.2-dev" }
+lucet-module = { path = "../../lucet-module", version = "0.7.0-dev" }
 witx = { path = "../../wasmtime/crates/wasi-common/WASI/tools/witx", version = "0.8.4" }
 quote = "1.0"
 proc-macro2 = "1.0"
diff --git a/lucet-wiggle/macro/Cargo.toml b/lucet-wiggle/macro/Cargo.toml
index 8e11ce0c0..efa1056fa 100644
--- a/lucet-wiggle/macro/Cargo.toml
+++ b/lucet-wiggle/macro/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucet-wiggle-macro"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
 license = "Apache-2.0 WITH LLVM-exception"
@@ -12,7 +12,7 @@ edition = "2018"
 proc-macro = true
 
 [dependencies]
-lucet-wiggle-generate = { path = "../generate", version = "0.6.2-dev" }
+lucet-wiggle-generate = { path = "../generate", version = "0.7.0-dev" }
 wiggle-generate = { path = "../../wasmtime/crates/wiggle/generate", version = "0.15.0" }
 witx = { path = "../../wasmtime/crates/wasi-common/WASI/tools/witx", version = "0.8.4" }
 syn = { version = "1.0", features = ["full"] }
diff --git a/lucetc/Cargo.toml b/lucetc/Cargo.toml
index 7a032d603..2f56c9b0f 100644
--- a/lucetc/Cargo.toml
+++ b/lucetc/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lucetc"
-version = "0.6.2-dev"
+version = "0.7.0-dev"
 description = "Fastly's WebAssembly to native code compiler"
 homepage = "https://github.com/fastly/lucet"
 repository = "https://github.com/fastly/lucet"
@@ -24,9 +24,9 @@ cranelift-module = { path = "../wasmtime/cranelift/module", version = "0.62.0" }
 cranelift-object = { path = "../wasmtime/cranelift/object", version = "0.62.0" }
 cranelift-wasm = { path = "../wasmtime/cranelift/wasm", version = "0.62.0" }
 target-lexicon = "0.10"
-lucet-module = { path = "../lucet-module", version = "=0.6.2-dev" }
-lucet-validate = { path = "../lucet-validate", version = "=0.6.2-dev" }
-lucet-wiggle = { path = "../lucet-wiggle", version = "=0.6.2-dev" }
+lucet-module = { path = "../lucet-module", version = "=0.7.0-dev" }
+lucet-validate = { path = "../lucet-validate", version = "=0.7.0-dev" }
+lucet-wiggle = { path = "../lucet-wiggle", version = "=0.7.0-dev" }
 wasmparser = "0.51.2"
 clap="2.32"
 log = "0.4"